76 



THE IRRIGATION AGE. 



CURRENT WHEELS. 



BY R. A. FARNUM, 

 Iowa State College. 



When a farmer enters a new country where irri- 

 gation is necessary he must determine, first, how he 

 ma} 7 best deliver water to his land. The agricultural 

 land in the semi-arid regions of the West is nearly 

 always smooth and usually has a gentle slope with and 

 toward some natural drainage channel. The stream 

 from which he proposes to draw his supply of water 

 ha.s a large fall, so that a ditch taken from it with a 

 moderate grade can recede rapidly and hence cover a 

 large area in a short distance. But in many cases 

 these ideal conditions do not prevail, or where only a 

 small irrigator wants to tap a stream in such instances 

 some other resources must be put into use. Water 

 wheels and motors unnumberable have been installed 

 to accomplish this purpose. All of them have their 

 advantages and disadvantages. The devices used to ac- 

 complish this work must be those whose power of ope- 

 ration is furnished by the current of the stream and 

 not affected by high or low water. The theory of the 

 current wheel, or the way in which it receives its power, 

 is by the impulse or dynamic pressure of moving 

 water. In its simplest form, a current wheel consists 

 of a large skeleton roller made of wood, with paddles 

 projecting beyond its rim. It is hung on a shaft and 

 supported at both ends by piers or posts, so as to al- 

 low the wheel to dip into the water to the width of 

 the paddles. The simplest device for raising water 

 with such a wheel is a row of buckets placed on the 

 rim so as to fill at the bottom of the wheel and empty 

 into a trough near the top. A more complicated way 

 is to connect the wheel to chain and bucket gear, or to 

 a pump. of some sort. These more difficult methods of 



construction are necessary in all cases where it is de- 

 sired to raise the water to a height greater than the 

 diameter of the wheel used. However, these wheels 

 should be so constructed in a simple and practical 

 manner, relieved of all complicated mechanical de- 

 vices, so that any fanner or ranchman can operate and 



keep in repair the same as he would any piece of farm 

 machinery owned by him. 



A very simple current wheel in operation on the 

 Grand Valley Canal, in Colorado, as shown in -Fig. 9, 

 raises water thirty feet for irrigation of forty acres of 



CURRENT MOTOR 



orchard. The wheel is thirty-four feet in diameter, 

 the paddles being eight feet long and two feet eight 

 inches wide. The spokes are secured at the center by 

 means of castings and are set at such angle to the 

 shaft that they come to a point on the rim of the 

 wheel. To provide sufficient rigidity a system of braces 

 is adopted, making a very substantial construction. 

 Braces are also run from paddle to paddle and be- 

 tween the arms of the wheel, so as to form a system 

 of six or eight circular rims. The bucket consists of 

 long boxes made of 1-inch stuff, set at such angle on 

 the rim of the wheel that they will fill nearly full and 

 raise the water within > two feet of the top of the 

 wheel. Under ordinary conditions this wheel will 

 raise about 0.25 cubic feet per second. This wheel is 

 estimated to have cost in the neighborhood of $400. 



Another device for lifting water is the chain and 

 bucket apparatus shown in Fig. 9. It is run by a 5- 

 foot overshoot wheel of ordinary construction. The 

 elevator consists of two endless chains running over 

 sprocket-wheels, each chain carrying twelve galvanized- 

 iron buckets, as shown in drawing. The lower sprocket- 

 wheels are thirty-two inches in diameter on a 1%- 

 inch shaft. The sprockets are set eighteen inches apart 

 and the distance between shafts is twenty feet. The 

 apparatus cost about $250. This arrangement makes 

 it easy to place the whole apparatus near the bank of 

 a stream, or, if desired, the elevator could be placed at 

 any convenient distance. 



The current motor, another device for lifting 

 water, or, rather, pumping it, differs considerably 

 from the above described. The 'motive power of this 

 apparatus is deflection and leverage. Fig. 1 of the 

 drawing is a view looking down on motor. Fig. 2 is 

 a side view of motor. Fig. 3 is a view of tripping de- 



